Nature: A series of small earthquakes and the widening of the caldera in 2011 has increased interest in the state of the Santorini volcano, which belongs to a chain of islands in the Aegean Sea. Unsure whether the activity is a sign of an impending eruption, geologists from the Hellenic Centre for Marine Research are installing instruments to measure the sea floor’s vertical movement and deformation. They will also be monitoring the temperatures and chemistry of sea-floor vents. By measuring changes in the levels of magma and gases rising below the sea floor, the scientists should be able to determine whether the volcano is returning to a dormant state or potentially preparing for an eruption. The volcano, which last erupted in 1950, is best known for a series of eruptions in 1650 BC that are believed to have led to the destruction of the Minoan civilization on the nearby island of Crete.